IIluminated display system and process

ABSTRACT

An Illuminated display integrated with a fabric substrate, comprising a rear electrode formed on a portion of a front surface of the fabric substrate, the rear electrode being formed on the fabric substrate portion by applying a catalyst to the fabric portion and subsequently immersing the fabric portion in an electroless plating bath followed by immersing the fabric portion in an electrode bath, a dielectric layer formed onto the fabric substrate surface substantially over the rear electrode, a light emitting layer formed onto the dielectric layer, a transparent conductive layer formed onto the light emitting layer; and a front electrode lead electrically connected to the transparent conductive layer to transport energy thereto.

RELATED APPLICATIONS

This application is a divisional to U.S. patent application Ser. No.10/104,161, filed Mar. 22, 2002, Entitled “Illuminated Display SystemAnd Process” which claims priority to U.S. application Ser. No.60/277,829, filed Mar. 22, 2001, entitled “PROCESS FOR INTEGRATING ANILLUMINATED DISPLAY WITH FABRIC”, which is incorporated herein byreference.

BACKGROUND OF THE INVENTION

Field of the Invention

This invention relates generally to applications for using illuminateddisplays, and more particularly, for integrating electroluminescentlight emitting panels with articles of fabric or textiles.

Problem

Electroluminescent (EL) panels or lamps provide illumination for a widearray of objects such as watches, vehicle instrument panels, computermonitors, etc. These EL panels are typically formed by positioning anelectroluminescent material, such as phosphor, between two electrodes,one of which is essentially transparent. The electric field created byapplying an electric current to the electrodes causes excitation of theelectroluminescent material and emission of light therefrom, which isviewed through the transparent electrode. Advancements in materialsscience have led to the formation of EL panels from thin, elongate,flexible strips of laminated material having a variety of shapes andsizes.

It is desired to have an illuminated display integrated into a fabric ortextile application, such that a light source can be created onclothing, backpacks, tents, signs, and the like. However, forming anelectroluminescent panel onto fabric presents a particular challengebecause of the flexible nature of fabric and the uses to which it isput, such as being worn as an article of clothing. Unlike an EL panelhung on a wall or in a window, electroluminescent panels attached tofabric must be put through repeated cycles of physical stress fromflexion of the fabric, and must be properly electrically and thermallyinsulated due to the increased risk of being touched by a person or wornclose to their body. Additionally, fabrics and textiles have generallyproven to be difficult substrates upon which to build the componentlayers of an EL panel. What is needed is a process for betterintegrating an EL panel with a fabric section to form a unitaryilluminated display system.

Electroluminescent film is commonly used in the display industry asback-lighting for liquid crystal displays. As constructed today, thesefilms are not transparent, or even semi-transparent since the backelectrode is either carbon or silver. It is thus also desirable to havea large area illumination source that is semi-transparent, i.e. itallows the observer to see an object through the back-side of the devicewhile it is illuminating the object.

Solution

The present invention involves processes for reliably forming thecomponent layers of an electroluminescent panel onto a fabric section tofacilitate construction of the entire EL panel assembly. In one aspect,the layers of an electroluminescent panel are formed integral with asubstrate section. First, a rear electrode made of a conductive polymeris formed onto a substrate section in a desired pattern. Then, adielectric layer is formed over the rear electrode layer. A lightemitting layer, transparent conductive layer made of a conductivepolymer, and front electrode lead are then successively formed onto thesubstrate section; the light emitting layer atop the dielectric layerand the transparent conductive polymer layer atop the light emittinglayer. Each of the component layers of the EL panel may be formed ontothe substrate section by a printing process. Optionally, the substratesection can be adhered to a substantially rigid backing while the ELpanel component layers are applied to aid in accurate placement of suchlayers. This aspect provides a construction where at least the rearelectrode is more fully integrated with the substrate section. When anelectric current is applied to the front and rear electrodes, anelectric field is created to excite the light emitting layer toilluminate.

Another aspect of the present invention provides a process whereby therear electrode of an EL panel is formed directly onto a fabric sectionusing a metalization process. An image is first formed to define aspecific design to be illuminated. The image is placed over a fabricsection to define an area for display and a catalyst is applied to suchdisplay area. Next, the portion of the fabric section with catalystapplied thereto is immersed in an electroless plating bath andsubsequently removed, which allows a chemical reduction to occur in theaqueous solution. Finally, the fabric section display area is immersedin an electrode bath to form an electrode layer that is integrated withthe fabric section and patterned in the associated image. The rest ofthe layers of the EL panel, including a front electrode, may be formedon top of the rear electrode and base fabric section by, for example, aprinting process. Upon energizing the EL panel, a light emitting layerwill illuminate in the pattern of the image.

In still another aspect of the present invention, an insulative layerand a process for forming thereof is provided to encapsulate a fabricsection having a rear electrode. The fabric section is first immersed inelectrophoretic liquid. An electrical lead is connected to the rearelectrode and a counter electrode is immersed in the liquid andconnected to an electrical lead of opposite polarity. Upon a voltagebeing applied to the electrical leads, an insulative conformal coatingis deposited on the fabric section immersed in the electrophoreticliquid. This coating maintains the integrity of the rear electrode andelectrically insulates such electrode, thereby mitigating the risk ofelectrical shock for a person touching the fabric. Furthermore, thecoating may serve as the dielectric layer of the electroluminescentpanel. A printing process or other means may be used to form theremaining layers of an EL panel on top of the dielectric layer.

By these processes, safer, more durable illuminated display systems canbe manufactured for all types of fabric and textile applications, suchas safety clothing (vests, jackets, hats, gloves), outdoor gear (tents,backpacks, etc.), flags and signs, or any other application requiring aflexible illumination solution. Additionally, because the EL panelcomponents of the illuminated display system may be formed together asthin layers by, for example, a printing process, thin EL lamps may beformed that are not too bulky or cumbersome to be worn on an article ofclothing. As opposed to reflective strips, the illuminated displayssystems formed by these processes do not require light to be reflectedoff of an EL panel surface from external light sources. Other advantagesand components of the present invention will become apparent from thefollowing description taken in conjunction with the accompanyingdrawings, which constitute a part of this specification and wherein areset forth exemplary embodiments of the present invention to illustratevarious features thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of an illuminated display system in accordance withan embodiment of the present invention.

FIG. 2 is a flowchart illustrating an exemplary process for forming theilluminated display system in accordance with an embodiment of thepresent invention.

FIG. 3 is a flowchart illustrating an exemplary process for performingthe metalization of a fabric substrate section in accordance with anembodiment of the present invention.

FIG. 4 is a flowchart illustrating an exemplary process forming aninsulative layer onto a fabric substrate section in accordance with anembodiment of the present invention.

FIG. 5 is a top plan view of the illuminated display system inaccordance with an embodiment of the present invention showing asubstrate and electroluminescent panel formed thereon.

FIG. 6 is a top plan view of a rear electrode formed onto a fabricsubstrate section system in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention provides a series of processes for formingelectroluminescent panel components onto substrates, preferably textilesand fabrics, to create illuminated display systems. In addition, certaincomponents of the display system may be formed together as disclosed inU.S. Pat. No. 6,203,391 of Murasko, the teachings of which areincorporated by reference herewith. The '391 patent discloses processesfor forming electroluminescent signs by combining electroluminescentlamp components with a sign substrate.

Conductive Polymer Illuminated Display

FIG. 1 presents an aspect of the present invention whereby a conductivepolymer is used to form the conductive elements of an electroluminescentpanel. This construction serves to better integrate the EL panel with asubstrate to form an illuminated display system 100. Conductive polymersthat may be used with EL panel 102 include polyaniline, polypyrrole, andpreferably, polyethylene-dioxithiophene, which is available under thetrade name “Orgacon” from Agfa Corp. of Ridgefield Park, N.J. Substrate104 forms the base layer upon which EL panel component layers areformed. Preferably, substrate 104 is a fabric or textile section suchthat the conductive polymer material can be at least partially absorbedinto the fabric fibers, forming a more integral structure. Suitablefabric or textile materials include cotton, nylon, polyester,high-density polyethylene (e.g., Tyvek brand from DuPont Company ofWilmington, Del.), and the like. All of these materials are hereinafterreferred to as “fabric”. EL panel 102 comprises a conductive polymerrear electrode 106, a dielectric layer 108, a light emitting layer 110,a front conductive polymer layer 112, and a front electrode lead 114.Optionally, conductive pads 116 are electrically connected to conductivelead 114 and conductive polymer rear electrode 106 to bring electricalenergy to EL panel 102 from a power source to cause light emitting layer110 to illuminate. Also, front electrode lead 114 is preferably aconductive polymer front outlying electrode lead disposed substantiallyaround the perimeter of front conductive polymer layer 112.

Dielectric layer 108 is formed of a high dielectric constant material,such as barium titanate. Light emitting layer 110 is formed of materialsthat illuminate upon being positioned in an electric field. Suchmaterials may include non-organics, such as phosphor, or organics suchas light emitting polymers, as taught in U.S. patent application Ser.No. 09/815,078, filed Mar. 22, 2001, for an “Electroluminescent MultipleSegment Display Device”, the teachings of which are incorporated byreference herewith. Conductive pads 116 are preferably made of silver,but may be fabricated from any conductive material from which a reliableelectrical connector can be formed.

FIG. 2 is a flow chart showing an exemplary sequence of steps forfabricating the electroluminescent panel 102 onto the substrate 104 toform the illuminated display system 100 shown in FIG. 1. Each of thecomponent layers 106 -116 of EL panel 102 may be successively appliedonto substrate 104 by a variety of means, including stenciling, flatcoating, brushing, rolling, and spraying, but preferably are printedonto the substrate by screen or ink jet printing.

If the chosen substrate 104 is made of a flexible material, such as afabric, substrate 104 is preferably attached to a rigid backing (notshown) using an adhesive before EL panel 102 is built thereon, as shownat step 201. The backing may be of a material such as aluminum,polycarbonate, cardboard, and the like. The adhesive must providesufficient bonding as to hold substrate 104 in place, but not so strongas to prohibit the removal of the substrate by applying a force to peelthe substrate away from the backing. Suitable adhesives for this purposeare contact adhesives such as “Super 77” from 3M Corp. of St. Paul,Minn.

At step 202, conductive polymer rear electrode 106 is applied onto afront surface 118 of substrate 104, preferably by printing. Electrode106 may be applied generally as a sheet layer covering the entiresubstrate 104, or may be patterned in a specific arrangement onsubstrate surface 118 to cover only the area desired to be illuminated(i.e. the surface area covered by the light emitting layer 110).Preferably, electrode 106 is made from polyethylene-dioxithiophene,which can be applied by screen printing to form a layer thickness in therange of approximately 0.1 and 50 microns (1 micron=1×10−6 meters).

Dielectric layer 108 is then applied onto substrate surface 118 over therear electrode 106, preferably by printing, at step 203. As an example,dielectric layer 108 comprises a material having a high dielectricconstant, such as barium titanate dispersed in a polymeric binder toform a screen printable ink. More than one dielectric layer may beapplied to better isolate the rear electrode 106 from other componentsof the electroluminescent panel 102 and reduce the risk of shortcircuiting. In addition, if better insulative properties are needed fromthe dielectric, an insulative coating may be applied over the dielectriclayer 108 to further reduce the risk of contact between conductivecomponents of the EL panel 102. As with rear electrode 106, dielectriclayer 108 may cover the entire substrate surface or merely the areadesired to be illuminated. Preferably, to reduce the risk of shortcircuiting of the EL panel 102 from the conductive layers 106, 112, 114coming into contact with one another, dielectric layer 108 is configuredto extend outward along the substrate surface 118 beyond theillumination area by approximately {fraction (1/16)} inches to {fraction(1/8)} inches. In an exemplary embodiment, dielectric layer 108 may beapplied on the substrate surface 118 to have a thickness of betweenapproximately 15 to 40 microns. In an alternative embodiment, dielectriclayer 108 may be omitted from the EL panel 102 if light emitting layer110 is an organic material, such as light emitting polymer, thatexhibits properties of a dielectric material.

At step 204, light emitting layer 110 is applied onto substrate surface118 over dielectric layer 108, preferably by printing. The surface areadimensions of the layer 110 define the illumination area for theelectroluminescent panel 102 (e.g., the letter “L”, a logo or iconimage, etc.). Light emitting layer 110 may be formed of either organic(i.e. light emitting polymers) or non-organic materials, and preferablyis a phosphor layer of electroluminescent particles, e.g., zinc sulfidedoped with copper or manganese which are dispersed in a polymericbinder, and having a thickness of about 0.1 to 100 microns. However, thechosen material will depend on the illumination application desired andthe power source available to energize the conductors, as light emittingpolymers and other organics do not require as high an illuminationvoltage as non-organic illumination materials.

The conductive polymer chosen for front conductive polymer layer 112 isone that is light-transmissive (i.e. transparent or translucent) suchthat the illumination provided by light emitting layer 110 may be viewedabove electroluminescent panel 102 by an observer. Preferably, thematerial forming layer 112 is polyethylene-dioxithiophene. At step 205,conductive polymer layer 112 is applied onto substrate surface 118 overlight emitting layer 110. Conductive polymer layer 112 extends outwardalong the substrate surface 118 at least to cover light emitting layer110, but preferably not beyond the perimeter of dielectric layer 108. Inthis way, conductive polymer layer 112 works in conjunction withelectrode 106 to provide a consistent electric field across the entiresurface of the light emitting layer to ensure even illumination of theEL panel 102. Conductive polymer layer 112 preferably has a thicknessbetween about 0.1 to 100 microns, and is preferably applied by printinglayer 112. If dielectric layer 108 extends substantially beyond aperimeter of the rear electrode, conductive layer 112 may extend outwardalong dielectric layer 108 a greater distance than the perimeter of rearelectrode 106.

At step 206, front electrode lead 114 is placed into electrical contactwith front conductive polymer layer 112 and is configured to transportenergy to such layer. In a preferred arrangement, front electrode lead114 extends substantially or completely around the perimeter of theconductive polymer layer 112 to ensure that electrical energy isessentially evenly distributed across layer 112. This configurationprovides front electrode lead 114 as a front outlying electrode.Optionally, if conductive layer 112 extends beyond the perimeter of rearelectrode 106, front electrode lead 114 may be positioned such that itdoes not substantially overlap the inwardly disposed rear electrode 106.Front electrode lead 114 is typically a {fraction (1/16)} inch to{fraction (1/8)} inch wide strip and approximately 2 to 20 percent ofthe width of conductive polymer layer 112, and may be positioned todirectly overlie one or more of the conductive layer 112, dielectriclayer 108, or substrate front surface 118. Preferably, front electrodelead 114 is made of a transparent conductive polymer such aspolyethylene-dioxithiophene allowing lead 114 to overlap conductivepolymer layer 112 and light emitting layer 110 without impeding theviewing of the EL panel illumination. Preferably, lead 114 is printed.

At step 207, conductive pads 116 are electrically connected to frontelectrode lead 114 and conductive polymer rear electrode 106 to supplyelectrical energy to EL panel 102 from a power source (not shown). Asseen in FIG. 5, conductive pads 116 may be printed onto substrate 104 aslead tails 115 extending to the perimeter of the substrate 104, or maybe fabricated as interconnect tabs extending beyond the substrate tofacilitate connection to a power source or controller. Preferably,conductive pads 116 are made of silver to provide a reliable electricalconductor.

In a preferred aspect where substrate 104 is a fabric section, theilluminated display system 100 is placed in an oven to cure for 2.5minutes at approximately 200 degrees Fahrenheit at step 208. Thistemperature ensures proper curing of the electroluminescent panel 102components while not distorting or damaging the fibers of the fabric.The system 100 is then removed from the oven.

At step 209, and in the aspect where the substrate is attached to arigid backing, substrate 104 is then removed from the backing,preferably by peeling substrate 104 away from the backing, to reveal theintegrated EL panel 102 and substrate 104 as illuminated display system100.

Optionally, a background layer or sign substrate (not pictured) havingcertain transparent and optically opaque areas can be placed over the ELpanel as taught in the '391 patent to form a specific illuminateddesign. The background layer may, for example, be formed of number ofcolored printable inks. Further, an insulative protective layer, such asan ultraviolet coating or a urethane layer, may be placed over EL panel102 and onto the substrate rear surface 120 to reduce the risk ofelectrical shock from a person coming into contact with conductiveelements of the illuminated display system 100.

In accordance with another embodiment, any of conductive polymer rearelectrode 106, front conductive polymer layer 112, and front electrodelead 114 may be formed of material other than a conductive polymer solong as at least one of rear electrode 106, conductive layer 112 andlead 114 is made of a conductive polymer. As an example, rear electrode106 can be made of conductive materials such as silver or carbonparticles dispersed in a polymeric ink; conductive layer 112 may be madeof transparent conductive materials such as indium-tin-oxide; frontelectrode lead 114 may be made of the same materials as rear electrode106, so long as lead 114 does not cover a significant portion ofconductive layer 112 and thereby block the light emitted through layer112.

It has been further determined that the above construction ofilluminated display system 100 having all layers fabricated fromtransparent or translucent conductive polymer produces a device thatacts as an electro-optical directional device. Using the arrangement ofelements shown in FIG. 1, in an alternative embodiment, asemi-transparent display device 102 is prepared by first applying aconductive polymer film layer to substrate 104 to form rear electrode106. In this embodiment, substrate may be either a non-fabric materialsuch as polycarbonate film, or a fabric. A dielectric film layer 108(e.g., barium titanate dispersed in a polymer matrix) is then depositedon top of rear electrode 106, followed by a light emitting film layer110 and a second layer of conductive polymer film to form frontconductive layer 112. In an exemplary embodiment, light emitting layer110 comprises a phosphor layer of electroluminescent particles, e.g.,zinc sulfide doped with copper or manganese which are dispersed in apolymer matrix. Upon application of a voltage (a square wave ofapproximately 380 volts p-p at approximately 400 HZ) across rearelectrode 106 and front conductive layer 112, the device emits lightmostly in the direction shown by arrow 130 in FIG. 1.

All layers of transparent or translucent when viewed therethrough in atleast one direction when the EL panel is being powered for illumination.When the display is placed front-side down on a high contrast printedsurface (e.g., newsprint, map, etc.), the printed image is clearlyvisible by an observer looking from the backside of the device throughthe dielectric. Light is reflected off the surface of the object backthrough the layer stack to the observer. For example, when a powersource is provided to electroluminescent panel 102 to cause lightemitting layer 110 to illuminate, items positioned below system 100 whenfront conductive polymer layer 112 is positioned face down on such itemsare illuminated and viewable through EL panel 102. Conversely, whenfront conductive polymer layer 112 is positioned face up in relation tothe item located directly below substrate 104, system 100 is opticallyopaque, preventing the viewing of the item through EL panel 102. Thepresent method is suitable for fabricating devices that are screenprinted onto non-fabric materials such as polycarbonate film, as well asfabric sections. This type of illumination method may also be used as alight source for E-ink or other electrochromic display devices with highcontrast.

FIG. 3 shows the process steps to perform the metalization of a fabricsubstrate section. Once the metalization process is complete, therebyforming a rear electrode of an electroluminescent panel, the remainingEL panel components can the be built onto the metalized fabric sectionto form an illuminated display system. Suitable metals for use in themetalization process are those that serve as both good electrodes andalso have the capability of being coated onto fabrics using standardelectroless plating procedures. Examples of metals that are suitable forthis process include copper, nickel, and other metals exhibiting similarcharacteristics. The use of fabrics as substrates upon which the rearelectrode and other EL panel components are formed allows the rearelectrode to efficiently bond to the fabric fibers, forming a moreintegral structure. Suitable fabric or textile materials include cotton,nylon (e.g., rip-stop), polyester, high-density polyethylene (e.g.,Tyvek brand from DuPont Company of Wilmington, Del.), and the like. Themetalization process employs the use of an electroless plating bath anda conductor bath to form a thin, flexible, conductive electrode in adefined shape integrated with a section of fabric.

In accordance with one embodiment, an image, such as a word, logo, icon,etc., is generated on a film transparency at step 301. This imagecorresponds to the area desired to be illuminated by anelectroluminescent panel. The transparency chosen should be one that maybe used by a printing device to burn the image into a photographicemulsion and may include transparencies made from plastics,polycarbonates, and similar materials. As an example, the image may begenerated on the transparency using a computer graphics program.

At step 302, the film transparency with the image thereon is burned intoa photographic emulsion, so that the image may be used with a printingdevice, such as a screen printer.

At step 303, the printing device is positioned over the fabric sectionand a catalyst solution is applied to a surface of the fabric. In thisway, the catalyst solution will be positioned on the fabric section inthe shape of the desired image. It should be noted that steps 301 and302 may be omitted if a device besides a printing device is used toapply the catalyst solution to the fabric in the shape of the image.

The fabric section with catalyst thereon is then immersed in anelectroless plating bath at step 304. This step allows a chemicalreduction to occur in the bath. It is not necessary for the entirefabric section to be immersed in the bath, merely the portion of fabricsection with the catalyst. The fabric section is then subsequentlyremoved and allowed to dry.

At step 305, the fabric section and applied catalyst are immersed in anelectrode bath, preferably an aqueous solution containing metallicparticles such as copper, nickel, or other metals exhibiting similarconductive characteristics. The metallic particles then migrate throughthe bath to the catalyst, depositing on the fabric surface in the shapeof the image. As with the electroless plating bath, it is only necessaryto immerse the portion of fabric section with the catalyst into theelectrode bath. The fabric section then subsequently removed and allowedto dry.

As a result of these process steps, a fabric section is formed with arear electrode thereon that is electrically conductive in the pattern ofthe image (i.e. in the desired illumination area). The rear electrodeformed from this process typically has a thickness of betweenapproximately 0.1 and 100 microns. The remaining layers of anelectroluminescent panel, including the dielectric layer, the lightemitting layer, the transparent conductive layer, and the frontelectrode lead, may be formed onto the rear electrode as discussed insteps 203-207 of FIG. 2 regarding the conductive polymer illuminateddisplay. Additionally, the transparent conductive layer and frontelectrode layer may be made of either conductive polymers, orinorganics, such as indium-tin-oxide for the transparent conductivelayer and silver or carbon particles dispersed in a polymeric binder forthe front electrode lead. In addition, an insulative protective layer,such as an ultraviolet coating or a urethane layer, may be placed overEL panel components and onto the fabric substrate rear surface 120 toreduce the risk of electrical shock from a person coming into contactwith conductive elements of the illuminated display system 100. When anelectric potential is applied across the rear electrode and the frontelectrode lead, the light emitting layer will illuminate in the patternof the image formed by the rear electrode. The rear electrode producedby this process is pliable and can be applied to fabric more easily thata typical silver or carbon electrode. Thus, such a rear electrode designwill prolong the life of an EL panel system attached to an article offabric.

Insulative Layer Formation

Subsequent to performing the process for the metalization of a fabricsubstrate section, an insulative layer may be applied to the fabricsubstrate section to encapsulate the fabric, providing uniforminsulation and reducing the risk of electric shock or short circuit ofan electroluminescent panel formed onto the fabric section. However, itis to be understood that the insulative layer formation process may beused with fabric section having rear electrode formed thereon by aprocess other than the fabric metalization process described above. Oncethe insulative layer is formed onto the fabric section, it serves as adielectric layer, allowing the remaining EL panel components to be builtthereon to form an illuminated display system. Suitable fabric materialsfor this process include cotton, nylon (e.g., rip-stop), polyester,high-density polyethylene (e.g., Tyvek brand from DuPont Company ofWilmington, Del.), and the like. The process steps for forming theinsulative layer are shown in FIG. 4.

At step 401, the fabric section having the rear electrode formed thereonis immersed in a vessel containing electrophoretic liquid. If desired,the entire fabric section may be immersed in the electrophoretic liquidto form an insulative layer over the entire fabric section, not merelythe portion where the rear electrode is located. However, as shown inFIG. 6, a small area of a lead tail 115 of the rear electrode 106,preferably about 0.25 inches in length and width, should be covered soas to avoid exposure to the electrophoretic liquid to enable aconductive pad 116 to be attached thereto to bring electrical energy tothe rear electrode 106.

A counter electrode is positioned in the electrophoretic liquid adjacentto the fabric section at step 402. The counter electrode can be made ofany conductive material, e.g., a metal such as copper or nickel. In thisway, the electrophoretic liquid vessel has two electrodes positionedtherein: the rear electrode of the fabric section and the counterelectrode.

At step 403, a voltage source, such as a DC power supply (or a battery),is attached to the fabric section rear electrode and the counterelectrode. A first lead of one polarity (i.e. positive or negative)electrically connects the voltage source to the rear electrode and asecond lead of opposite polarity of the first lead electrically connectsthe voltage source to the counter electrode. The first lead preferablyconnects to the area of the lead tail 115 that is covered from exposureto the electrophoretic liquid.

At step 404, the voltage source creates a potential difference betweenthe fabric section rear electrode and the counter electrode, causing theflow of electrical energy through the electrophoretic liquid. Thisprocess causes an insulative conformal coating to deposit onto at leastthe rear electrode of the fabric section, and preferably, onto theentire fabric section that is immersed in the electrophoretic liquid.The insulative coating will typically be formed onto the fabric sectionat a thickness between approximately 0.1 and 100 microns.

At step 405, the fabric section is removed from the electrophoreticliquid, and then rinsed and allowed to dry. Optionally, an insulatingprotective layer, such as an ultraviolet coating or a urethane layer,may be formed on both sides of the fabric over areas having a metalcoating or conductor to protect persons who touch the fabric fromelectrical shock.

The insulative conformal coating provides a number of benefits informing an electroluminescent panel onto a fabric section. First, thecoating maintains the integrity of the rear electrode and electricallyinsulates such electrode on both the front and rear surfaces of thefabric section, thereby mitigating the risk of electrical shock for aperson touching the fabric. Also, the coating may encapsulate the entirefabric section immersed in the electrophoretic liquid, thereby providinguniform insulation to eliminate short circuiting from other conductiveelements of an EL panel formed onto the fabric. Furthermore, the processshortens the manufacturing of an EL panel in that the insulating barriercan serve as a dielectric layer, whereby the light emitting layer, thetransparent conductive layer, and the front electrode lead are appliedthereon as discussed in steps 204-207 of FIG. 2 regarding the conductivepolymer illuminated display. Additionally, and as with the metallizedfabric process, the transparent conductive layer and front electrodelayer may be made of either conductive polymers, or inorganics, such asindium-tin-oxide for the transparent conductor and silver or carbonparticles dispersed in a polymeric binder for the front electrode lead.When an electric potential is applied across the rear electrode and thefront electrode lead, the light emitting layer will illuminate in thepattern of the image formed by the rear electrode.

The invention thus attains the objects set forth above, among thoseapparent from preceding description. Since certain changes may be madein the above systems and methods without departing from the scope of theinvention, it is intended that all matter contained in the abovedescription be interpreted as illustrative and not in a limiting sense.

1. A method for forming an insulative conformal coating around anelectrically conductive fabric substrate, comprising: placing the fabricsubstrate in electrophoretic liquid; placing a counter electrode in theelectrophoretic liquid; applying a voltage to the substrate and thecounter electrode; and wherein the insulative conformal coating isformed around the substrate.
 2. The method of claim 1, wherein thefabric substrate is made from materials comprising at least one materialselected from the group consisting of cotton, polyester, nylon, andhigh-density polyethylene.